You're obviously behind on video game series. The Super Smash Bros. Franchise has been around for WAY longer then the Kingdom Hearts franchise. If anyone did any stealing of ideas, it'd of been Square Enix.
I honestly can't help you too much with tips and tricks for the game. I can only say learn when to block and when to dodge. Beyond that, I normally just use whatever moves would work best in the situation.
And how to kill Toon Link? If you can't kill him, I don't believe you can take Olimar.
But let me see, Toon Link has the same move set as Link. So first you've gotta figure out how to take down Link. Try to stay ground focused when fighting a smaller character and know where exactly your attacks hit. Aerial combat against smaller targets is just begging to get your arse handed to ya. On the ground, Larger characters will dominate. And stay near him at all costs. That will render his bow and bombs uselesss, unless he's suicidal.
Oh, on a side note, if you're looking for a good online version of brawl I suggest going to this website
arrow http://www.mcleodgaming.com/games.phpAnd playing the newest demo of SSF2